1. Field of the Invention
The invention is directed to the joining together of two electrical cords and, more particularly, to a mechanism which can be incorporated into female electrical connectors to lock an inserted male connector to such female connector.
2. Description of the Prior Art
By the use of electrical extension cords, electrical devices, such as tools, lamps, appliances and the like can be used at a distance from the source of electrical power, such as a wall outlet. The electrical device has a male connector or plug which is plugged into a female connector or socket at one end of the extension cord while the male connector at the other end of the extension cord is plugged into the outlet. If the tool or appliance being used is moved during such use the device plug may be pulled free of the extension cord and thus prevent further use until the plug and socket are rejoined. Such plug/socket separation can be a major problem if the user is remote from the plug/socket joint as on a ladder, a roof or similar place.
One approach to prevent the unwanted separation of male plugs from female sockets is the use of external, mechanically operated plug and socket clamps of the type shown in U.S. Pat. No. 4,664,463 issued May 12, 1987 for "Plug and Connector Clamp" by Robert A. Carmo and U.S. Pat. No. 5,393,243 issued Feb. 28, 1995 for "Releasable Cord Connecting Lock" by Robert A. Carmo, both assigned to the instant assignee. Although these devices work well, they do require that an extra mechanism be used and that the user remember to take it along to the end of the extension cord.
U.S. Pat. Nos. 5,129,836 issued Jul. 14, 1992 and 5,281,162 issued Jan. 25, 1994, both directed to "Self-Locking Female Receptor For Electrical Cord" by Nels E. Ursich show a mechanism for locking the blades of a male plug in a housing. However, there is no disclosure as to how to use the mechanism to join a plug and socket. Further, the devices use locking balls which must be properly placed with respect to the male plug blades to lock or release such blades from the female receptor.